Coke Deposition on Pt-Based Catalysts in Propane Direct Dehydrogenation: Kinetics, Suppression, and Elimination

Pt-based catalysts are widely used in propane dehydrogenation to meet the dramatically increased demand of propylene from an on-purpose catalytic process. Although the process has been commercialized with high selectivity for decades, the prevention of coke deposition is still a daunting challenge. Herein, in order to provide a full coverage of the impact of coke deposition, we critically analyze the process of coke formation on Pt-based catalyst. First, the intrinsic nature of coke, including composition, distribution, and effects, is presented. The developments of kinetics model of coke growth are discussed and compared to offer insight into mechanism of coke formation. Moreover, the focus is put on the ways to prevent coke, which included cofeeding reductant gas, promoter, and support engineering. The advantage and limitation of each method is well elaborated, and the unique working principle behind each prevention method is uncovered. The new developments of single atom/site and confined metal cluster strategies are indicated. The regeneration of the deactivated catalyst is also discussed, which has a direct influence on the coke elimination and metal dispersion. In the end, the possible optimization strategies are suggested for the future Pt catalyst rational design. The current work provides a comprehensive summary of the coke formation, which lays out a solid and essential base for the further developments of Pt catalysts in propane direct dehydrogenation.